Basic dye and process of making same.



U irE STATES PATENT OFFICE.

FRIEDRICH RUNKEL, OF ELBERFELD, GERMANY, ASSIGNOR TO FARBEN- FABRIKEN OF ELBERFELD (30., OF NEW YORK, N. Y.

BASIC DYE AND PROCESS OF MAKING SAME. v

SPECIFICATIGN formingpart of Letters Patent No. 677,279, dated June 25, 1901.

Application filed February 6, 1901. Serial No. 46,200. (No specimens.)

To all whom it may concern:

Be it known that LFRInnRIoH Runnnndoc tor of philosophy, chemist, (assignor to the FARBENFABRIKEN OF ELBERFELD Co. ,of New York,) residing at Elberfeld, Germany, have invented a new and useful Improvement in Reddish-Violet Basic Dyes; and I hereby declare the following to be a clear and exact description of my invention.

My invention relates to the production of new reddish-violet dyestuffs by condensing in the presence of mineral acids the auramins, having, for instance, the following general formula:

(in which formula R means an alkyl radical-- such as methyl, ethyl, or the 1ikeX, a hydrogen atom, which can be substituted by a methylic group) with alpha methylindole, (methy1keto1e,) described by E. Fischer, (see Annalcn cler Ohemie, Vol. 236, p. 126,) and having the following formula:

l l o In this process the group-fill of the auraminis replaced by the radical of alpha-methylindole, the ammonium salt of the respective mineral acid being formed as by-product and the salts of the bases of the new coloringmatters are thus produced directly. The said new dyestuffs are, in the shape of the mineral-acid salts, dark-brown powders,which are readily soluble in water with a reddishviolet color, which is not essentially changed by the addition of dilute mineral acids. They are also readily soluble in alcohol with a reddish-violet color and are dissolved by concentrated sulfuric acid of 66 Baum with a yellowish-brown color. They dye cotton morown,

- danted with tannin, wool, and silk reddishviolet shades fast to the action of dilute mineral acids.

In carrying out my new process practically I can proceed as follows, the parts being by weight: A solution prepared from fifteen parts of pure aurainin G, having the formula:

CH3 CH3, and 6.5 parts of alpha-methylindole in sixty five parts of a thirty-per-cent. hydrochloric acid is heated for about from one to two hours on a water-bath. The yellow colorof the solution slowly turns brown. Subsequently it is stirred into about seven hundred parts of icewater, which is mixed with about one hundred parts of a watery solution of common salt. By means of this operation the new dyestuff is separated in the shape of dark flakes. It is filtered 01f, pressed, and dried at about from 80 to 90 centigrade. I

When dry and pulverized, the new dye stuff thus obtained is a dark-brown powder, readily soluble in water and in alcohol with a reddish-violet color. By the addition of caustic alkalies, alkaline carbonates, or ammonia to its watery solution the free base of the dyestuif is precipitated in the shape of orange-yellow flakes. In concentrated sulfuric acid (of 66 Baum) it is dissolved with a yellowish-brown color, which is not changed by the addition of a small quantity of ice, while a reddish-violet solution is obtained on adding a larger quantity of ice.

The new coloring-matter dyes cotton mor danted with tannin, wool, and silk clear reddish-violet shades fast to the action of dilute mineral acids. The same dyestufis can also be obtained by condensing the thio-ketones of the general formula:

H \Ph (R meaning in this formula an alkyl radicalsuch as methyl, ethyl, or the like-X meanin g a hydrogen atom which can be substituted by a methylic group) or the respective ketones with alpha-methylindole in the presence of R meaning an alkyl radical and X meaning a hydrogen atom which can be substituted by a inethylic group with alpha-methylindolein the presence of mineral acids, and then isolating the resulting dyestuffs from the reaction mixture, substantially as hereinbefore described.

2. The process for producing a new basic dyestuff, which process consists in first treating the dyestuff havingthe following formula:

with alpha-methylindole in the presence of mineral acids and then isolating the resulting dyestuif from the reaction mixture, sub stantially as hereinbefore described.

3. The herein-described new basic dyestuffs being, when dry and pulverized, dark-brown powders readily soluble in water with a reddish violet color which is not essentially changed by the addition of dilute mineral acids, also readily soluble in alcohol with a with alpha-methylindole in the presence of mineral acids, being, when dry and pulverized, a dark-brown powder readily soluble in water and in alcohol with a reddish-violet color, the free base of the dyestuff being separated in the shape of orange-yellow flakes by the addition of caustic alkalies, alkaline carbonates or ammonia to its watery solution; being dissolved by concentrated sulfuric acid of 66 Baum with a yellowish-brown color which is not changed by the addition of a small quantity of ice, while a reddish-violet solution is obtained on adding a larger quantity of ice to the sulfuric-acid solution, dyeing 70 cotton mordanted with tannin, wool and silk clear reddish-violet shades fast to the action of dilute mineral acids, substantially as hereinbefore described.

In testimony whereof I have signed my name in the presence of two subscribing witnesses.

FRIEDRICH RUNKE'L.

lvitnesses:

OTTO KONIG, J. ACHADDEJI. 

